Center.



m. ss|,os4, Patented Nov. 6,1900;

Y c. u. BUBWINKLE.

CENTER.

(Application filed June 25, 1900.)

(lo Iodal.)

FIG. 1.

W WITNESSES: INVENTOR:

mm m

m: Norms PFI'ERS ca worauma, WASHINGTON. n. c.

UNITED STATES PATENT OEFIQE,

CHARLES H. BURWINKLE, OF PHILADELPHIA, PENNSYLVANIA.

CENTER.

SPECIFICATION forming part of Letters Patent No. 661,034, dated November6, 1900.

Application filed June 25, 1900.. Serial No. 21,418- (No model.)

To all whom it may concern:

Be it known that LOHARLEs H. BURWINKLE,

a citizen of the United States, residing at Philadelphia, in the countyof Philadelphia and State of Pennsylvania, have invented oer-r tain newand useful Improvements in Centers, of which the following'is aspecification.

Centers, although. employed in the construction of buildings in variousconnections,

find their largest usefulness in bridging the usually removed andasuitable flooring placed across the upper surfaces of the I-beams and asuitable ornamental or other ceiling applied to the under surface of thecement and I- beams.

Inasmuch as I-beams are spaced at various distances apart and are ofvarious heights, and inasmuch as it is necessary in conforming tospecifications of buildings, to provide the cement masses of variouspredetermined thicknesses,-a matter determined in part by the spring'orheight of the arched center,- builders have been obliged to either keepon hand a large supply of centers representing the range of variation inbreadth and curve likely to be required, or else to specially constructsets of centers for each building upon which they may be engaged, eitherof which expedients involves considerable expense.

Furthermore, wooden centers as hitherto employed, have been cumbersome,and difficult to elevate to the upper portions of partly completedbuildings, and to place in position therein.

It is the object of my invention to provide a center so constructed asto be capable of being taken apart for convenience in transportationfrom one place to another, the parts of which may, by a single 'workman,be expeditiously and easily assembled to form an arch in any desiredlocation, the devices being of such construction, furthermore, as to beadapted to fit between I-beams separated by any ordinary distance, andto form an arch of any desired curvature,

In the accompanying drawings I show, and herein I describe, a good formof a convenient embodiment of my invention, the particularsubject-matter claimed as novel being hereinafter definitely specified.

In the accompanying drawings,

Figure 1 is a view in side elevation of a center embodying my invention,shown in position upon I-beams of usual construction.

Figures 2 and 3 are views in perspective of the keepers.

Similar letters of reference spending parts.

In the accompanying drawings,

a a are keepers, as I term them, mounted upon the lower flanges of theI-beams, g g, the two keepers employed in an arch facing each otheracross the interspace between the I- beams. Each keeper is provided witha suspension hookf, engaged over the lower flange of the I-beam on whichit is mounted, and with an adjusting screw or screws 6 in threadedengagement with its body, the advance ends of which screws are adaptedto engage against the under face of the beam.

Manifestly, as the Weight of the arch and any superposed material tendsto throw the outer ends of the basal portions of the keepers upwardtoward the I-beams, and maintain I indicate correthe advance ends of thescrews a constantly in contact therewith, the keepers may, bymanipulation of said screws 6, be set at any desired inclination withrespect to the I-beam.

Each keeper embodies a bar socket h, being conveniently, as shown, anopening eXtending through its base, and open at both ends, such socketsbeingintended for the reception of the respective ends of the bridge bar17.

b is what I term the bridge bar, being preferably a strip ot'steel orsuitable spring metal, of appropriate dimensions, conveniently arrangedto accurately fit within the sockets h, the respective ends of which barare, when the parts are assembled, entered'in the respective sockets ofthe two keepers with which the bar is associated, the central portion orbody, of the bar, remaining in the form of an arch between the I-beams.

The bridge bar is of length in excess of the ordinary distance betweenI'-beams between which the arch is arranged, and, when in position, oneor both of its ends projects beyond the keeper or keepers. The bar,havingthis excess of length, may, therefore, to increase the height ofits arched central portion, be drawn inward through the sockets, thedimensions of the arch being manifestly determined by the length of thebar existing between the two keepers.

When the bar has, by adjustment with respect to the keepers, been set toform an arch of the desired dimensions, binding screws 0, which passthrough the walls of the keepers and into the sockets 7L, may betightened up to bear against said bar and lock it in position. Ofcourse, the bar maybe adjusted by shifting one of its ends through itssocket in the keeper, the other end remaining fixed with respect to theother ke per. The arrangement set forth herein, however, which enablesthe bar to be adjusted by shifting either end through its socket, isdesirable, as sometimes one end may be close to a wall or very difficultof approach, whereupon it is very convenient to effect the necessarymanipulation at the other end.

A series of keepers and bridge bars are, of course, employed, at desiredintervals along the length of the I-beams and between each pair of saidbeams. Narrow boards d, or kindred devices, are then laid upon the uppersurfaces of the bridge bars, to complete the structure.

When the centers are thus in position, the concrete or other materialmay be placed upon them in the usual manner, as hereinbefore explained.

Centers made according to my invention maybe repeatedly used, andemployed in any location and forany purpose in and for which centers areordinarily used.

In my improved construction features of especial val ne reside in thefact that the keepers may be adjusted to hold the lower ends of thebridge bars at any desired angle, thus setting the arch, and in the factthat the body of the bar itself may be adjusted lengthwise to produceany desired amplitude of curve.

The weight of the load on the center does not, in my improvedconstruction, operate to spread the I-beams apart, but forces the outerends of the bases of the keepers upward, and through the screws e, bearsagainst the under faces of the I-beams, the keepers themselves tendingto rock or turn in the planes of the length of the bridge bars, on thepoints of contact of their hooksfwith the flanges of the beams.

Having thus described my invention, I claim 1. A supporting arch for acenter, consisting of a pair of keepers provided with books adapted toengage upon the upper edges of the flanges of I-beams, and with basesadapted to extend across the under faces of said I- beams, screwsextending through the bases of said keepers into contact with the underfaces of said I-beams to adjust the inclination of said keepers, barengaging devices formed in or on said keepers, a spring bar therespective ends of which are entered in said devices and freefoulongitudi'nal adjustment with respect thereto, and means for securingthe respective ends of said spring bars at various positions ofadjustment with respect to said devices.

2. The combination, to form a supporting arch for a center, of a springbar, means for engaging one end of said spring bar to the lower portionof an I-beam, and, as a means for connecting the other end of said barto the adjacent I-beam, a keeper consisting of a base, embodying asocket open at both ends, a hook extending from said base and adapted toengage upon the upper edge of the lower flange of the I-beam, a screwpassing through said base and adapted to engage the lower face of saidI-beam, and a binding screw engaged in said base and entering saidsocket.

3. A keeper or support for a center arch, consisting of a block or bodyprovided with a hook adapted to engage upon the lower flange of anI-beam, which hook sustains the weight of said body and permits its movement in a plane perpendicular to the axis of said beam, means carried bysaid block, and operative against the lower portion of the I- beam, foradjusting the set of said body in different positions in said plane ofmovement,

and means for engaging the end of a bridge bar, substantially as setforth.

4. A keeper or support for a center, consisting of a block or bodyprovided with a supporting hook adapted to engage upon the lower flangeof an I-bearn, to support the weight of said block, said block beingadjustable in a plane transverse with respect to the axis of the I-beam,a screw carried by said block adapted to abut against the lower face ofthe I-beam and by its set control the adjustment of the block, and meanscarried by said body or block for securing in different positions oflongitudinal adjustment, the end of a bridge bar, substantially as setforth.

5. A keeper or support for a center, consisting of a body or blockprovided with a hook adapted to engage upon the upper edge of the flangeof an I-beam, and formed with a base adapted to extend across the lowerface of said beam, a screw extending through said base into contact withthe lower face of said beam, and a bar engaging device formed in or onsaid keeper.

6. A keeper or support for a center, consisting of a body or block,provided with a hook adapted to engage upon the upper edge of the flangeof an I-beam, and formed with a base adapted to extend across the lowerface of said beam, a screw extending through said base into contact withthe lower face of said beam, and abar engaging device formed in or onsaid keeper and'adapted to secure a bridge bar in different positions oflongitudinal adjustment with respect thereto.

7. A keeper for a supporting arch, consisting of a body provided with ahook, a screw passing in an approximately vertical direction throughsaid body, a socket extend ing through said body for the reception of abridge bar, and a screw adapted to engage a In testimony that I claimthe foregoing as my invention I have hereunto signed my name this 23dday of June, .A. D. 1900. 7

CHARLES H. BURWINKLE.

In presence of t bridge bar extending through said socket, I F. NORMANIjIXON,

THos. K. LANCASTER.

substantially as set forth.

